To be 634 a prime number, it would have been required that 634 has only two divisors, i.e., itself and 1.

However, 634 is a semiprime (also called biprime or 2-almost-prime), because it is the product of a two non-necessarily distinct prime numbers. Indeed, 634 = 2 x 317, where 2 and 317 are both prime numbers.

Is 634 a deficient number?

Yes, 634 is a deficient number, that is to say 634 is a natural number that is strictly larger than the sum of its proper divisors, i.e., the divisors of 634 without 634 itself (that is 1 + 2 + 317 = 320).

Parity of 634

634 is an even number, because it is evenly divisible by 2: 634 / 2 = 317.

Is 634 a perfect square number?

A number is a perfect square (or a square number) if its square root is an integer; that is to say, it is the product of an integer with itself. Here, the square root of 634 is about 25.179.

Thus, the square root of 634 is not an integer, and therefore 634 is not a square number.

What is the square number of 634?

The square of a number (here 634) is the result of the product of this number (634) by itself (i.e., 634 × 634); the square of 634 is sometimes called "raising 634 to the power 2", or "634 squared".

Number of digits of 634

What are the multiples of 634?

The multiples of 634 are all integers evenly divisible by 634, that is all numbers such that the remainder of the division by 634 is zero. There are infinitely many multiples of 634. The smallest multiples of 634 are:

0: indeed, 0 is divisible by any natural number, and it is thus a multiple of 634 too, since 0 × 634 = 0

634: indeed, 634 is a multiple of itself, since 634 is evenly divisible by 634 (we have 634 / 634 = 1, so the remainder of this division is indeed zero)

How to determine whether an integer is a prime number?

To determine the primality of a number, several algorithms can be used.
The most naive technique is to test all divisors strictly smaller to the number of which we want to determine the primality (here 634).
First, we can eliminate all even numbers greater than 2 (and hence 4, 6, 8…).
Then, we can stop this check when we reach the square root of the number of which we want to determine the primality (here the square root is about 25.179).
Historically, the sieve of Eratosthenes (dating from the Greek mathematics) implements this technique in a relatively efficient manner.

More modern techniques include the sieve of Atkin, probabilistic algorithms, and the cyclotomic AKS test.